Matthew Castro says he's sorry about what he did at Wells Fargo & Co., and even sorrier about the people he did it to: Latinos not so different from himself.

Castro, 41, says he is one of the thousands of people Wells Fargo has fired for secretly opening accounts without customers' consent.

But for Castro, the scandal that has toppled the bank's longtime leader, John Stumpf, cuts especially deep. He says he and colleagues seized every opportunity to open sham accounts for Latinos, many of them recent immigrants.

"There would be times the client would sit down and leave without even knowing they had these new accounts," says Castro, whose father came to the U.S. from Colombia. He says he tried to lessen his guilt by doing volunteer work.

As Wells Fargo's new chief executive officer, Tim Sloan, tries to contain the scandal, Los Angeles authorities, former employees and community activists are raising an uncomfortable question: Did bank employees single out Latinos, particularly those without Social Security numbers or a strong command of English, as they opened legions of unauthorized accounts?

Wells Fargo says CEO John Stumpf and the executive who ran the bank's retail banking division will forfeit tens of millions of dollars in bonuses as the bank tries to stem a scandal over its sales practices.

The board of directors at the nation's second-largest bank said Tuesday that Stumpf will...

A spokeswoman for Wells Fargo, Richele Messick, denied the bank targeted anyone. And given the bank is a major player in the West and Southwest, where many Latinos live, the issue may boil down to geography.

But for Wells Fargo, the very suggestion stings. Wells has deeper roots in Hispanic communities than any other major bank and has actively courted Latinos in recent years.

The Federal Deposit Insurance Corp. and others have long urged immigrants in general, and those from Mexico in particular, to turn away from predatory financial players and embrace mainstream banks. Even with those efforts, nearly one in five Hispanic households were unbanked as of 2013, the most recent year for which FDIC statistics are available.

The possibility that Wells Fargo essentially profiled Hispanics has startled Latino communities, particularly at a time when immigration has become a divisive issue in the U.S. presidential campaign.

Sen. Sherrod Brown (D-Ohio) said Monday that he plans to push legislation that would allow Wells Fargo & Co. customers to sue the bank over unauthorized accounts opened by employees trying to meet aggressive sales quotas.

The escalating scandal also drew the attention of Democratic presidential...

"This is just unbelievable," said Brent Wilkes, national executive director of the League of United Latin American Citizens. "It's really upsetting to find out this is happening to the Latino population specifically because it seems like people go out of their way to make life tougher for Latinos."

The most serious allegations have been leveled by the city attorney's office in Los Angeles, Wells Fargo's biggest market and the bulwark of its stronghold in California.

After illegal sales practices at the bank first came to light several years ago, the city attorney spent 16 months investigating whether employees had singled out Latinos in order to hit aggressive sales targets.

Investigators alleged that Wells Fargo had in some cases targeted Mexican nationals with identification cards issued by consular offices.

Such Matricula Consular cards, which are often accepted as ID, enabled Wells Fargo employees to open unauthorized accounts for people without Social Security numbers, said Jim Clark, chief deputy to City Attorney Mike Feuer. Two former Wells Fargo executives in California, both of whom left within the last three years, corroborated those findings to Bloomberg. The executives spoke on condition they not be named to avoid hurting their careers.

"We based our allegations on 16 months' worth of work," Feuer told U.S. senators at a hearing last month. Los Angeles was among authorities including the federal Consumer Finance Protection Bureau that recently settled claims against Wells Fargo for $185 million.

Stumpf’s departure is a clear sign that the bank wishes to put its scandal, in which employees laboring under...

Messick, the Wells Fargo spokeswoman, said: "We have no indication that consular card customers were disparately impacted among the 2 million accounts we analyzed that may have been unauthorized."

Such assurances aside, Wells Fargo must now regain trust even in its hometown. A program called Bank on San Francisco, created by the city to address the needs of people without bank accounts, last month suspended the firm as a member.

Castro says he experienced Wells Fargo's aggressive sales culture up close. A Miami native who grew up speaking Spanish, he joined as a teller in 2008 in the Mission District, a hub for new immigrants from El Salvador, Mexico, Argentina, Nicaragua, Guatemala and Puerto Rico.

He says a supervisor was clear from the start: Castro was to sell as many as 13 "solutions" per day, and was encouraged to use his Spanish to bring in Latino customers. He says he quickly embraced the strategy.

At one point, Castro says, he went through his files and found a customer who had six separate accounts but no debit cards. He promptly opened six debit-card accounts without telling the client. He says he was fired within days after an internal audit revealed what he'd done.

"I didn't like what I was doing to the community, but I did what I had to do," Castro says. "The goals were so unattainable, and yet we had these clients who didn't seem to know any better."

Armando Rosales, who later became manager of the Mission branch where Castro worked, has sued Wells Fargo for racial discrimination. In a complaint filed in California last March, Rosales said he was promoted to maintain "a pattern of illegal practices" and was later criticized for reporting questionable behavior and failing to increase the branch's Spanish-speaking clientele.

His complaint goes on to say: "All too often, customers who were recent immigrants to the United States told Rosales of consumer fraud being perpetrated on them by Wells Fargo's branch employees."

Rosales, now a personal banker at Wells Fargo, was unsure whether senior management was aware of what he considered widespread unethical behavior, according to his lawyer, Niall Vignoles. But when Rosales raised the issue, he was ostracized, Vignoles said.

To Aracely Panameño, director of Latino affairs for the Center for Responsible Lending, the Wells Fargo affair will hamper broader efforts to get immigrants into the financial mainstream.

"We have spent a great deal of time trying to persuade folks that it's better to be banked than unbanked," she said. "This completely undermines all of that effort and reinforces the idea that people in the banking industry are out for themselves."